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Steffensen, J.P.; Andersen, K.K.; Bigler, M.; Clausen, H.B.; Dahl-Jensen, D.; Fischer, H.; Goto-Azuma, K.; Hansson, M.; Johnsen, S.J.; Jouzel, J.; Masson-Delmotte, V.; Popp, T.; Rasmussen, S.O.; Rothlisberger, R.; Ruth, U.; Stauffer, B.; Siggaard-Andersen, M.-L.; Sveinbjornsdottir, A.E.; Svensson, A.; White, J.W.C. (2008). High-Resolution Greenland Ice Core Data Show Abrupt Climate Change Happens in Few Years. Science, 321(5889), 680–684.
Abstract: The last two abrupt warmings at the onset of our present warm interglacial period, interrupted by the Younger Dryas cooling event, were investigated at high temporal resolution from the North Greenland Ice Core Project ice core. The deuterium excess, a proxy of Greenland precipitation moisture source, switched mode within 1 to 3 years over these transitions and initiated a more gradual change (over 50 years) of the Greenland air temperature, as recorded by stable water isotopes. The onsets of both abrupt Greenland warmings were slightly preceded by decreasing Greenland dust deposition, reflecting the wetting of Asian deserts. A northern shift of the Intertropical Convergence Zone could be the trigger of these abrupt shifts of Northern Hemisphere atmospheric circulation, resulting in changes of 2 to 4 kelvin in Greenland moisture source temperature from one year to the next.
Programme: 458
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Xu, G.; Frey, F.A.; Weis, D.; Scoates, J.S.; Giret, A. (2007). Flood basalts from Mt. Capitole in the central Kerguelen Archipelago: Insights into the growth of the archipelago and source components contributing to plume-related volcanism. Geochem. Geophys. Geosyst., 8.
Abstract: The Kerguelen Archipelago, constructed on the submarine Northern Kerguelen Plateau, is attributed to Cenozoic volcanism arising from the Kerguelen hot spot. Geochemical studies of 325 to 1000 m thick lava sections of the ?30 to 25 Ma flood basalt forming the bulk of the archipelago show a temporal change from older tholeiitic basalt to younger slightly alkalic basalt. This compositional transition is expressed in a 630 m lava section at Mt. Capitole where the lava sequence is lowermost tholeiitic basalt overlain by slightly alkalic basalt overlain by plagioclase-rich cumulates that are mixtures of plagioclase-phyric basalt and more evolved magmas. During growth of the archipelago, magma supply from the hot spot was variable and at times sufficiently low to enable extensive crystal fractionation; e.g., at Mt. Capitole and nearby Mt. Tourmente only 10 of 120 lava flows have >6 wt% MgO. On the basis of this study and previous isotopic data for the ?34 Ma submarine lavas erupted on the Northern Kerguelen Plateau, other flood basalt sections in the Kerguelen Archipelago, and younger lavas erupted in the archipelago and at Heard Island, there is significant Sr, Nd, Hf, and Pb isotopic heterogeneity that can be explained by two stages of mixing. The first mixing event, best shown by the submarine lavas, is between components that are related to Indian Ocean mid-ocean ridge basalt (MORB) and the Kerguelen hot spot. From ?34 Ma to <1 Ma, on average the proportion of the MORB-related component decreased. Subsequently, a second mixing process involved addition of a component with relatively high 87Sr/86Sr (>0.7060) and low 143Nd/144Nd (<0.5125) and 176Hf/177Hf (<0.2827) and nonradiogenic Pb isotope ratios (<17.9 for 206Pb/204Pb). We infer that this component was lower continental crust.
Keywords: Kerguelen mantle plume; Kerguelen Archipelago; Mt. Capitole; lower continental crust; Sr; Nd; Hf; Pb isotopic ratios; 1037 Geochemistry: Magma genesis and partial melting; 1038 Geochemistry: Mantle processes; 1065 Geochemistry: Major and trace element geochemistry
Programme: 444
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BOURGEON, S.; VIERA, V.M.; RACLOT, T.; GROSCOLAS, R. (2007). Hormones and immunoglobulin levels in king penguins during moulting and breeding fasts. Ecoscience, 14(4), 519–528.
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Legrand, M.; Preunkert, S.; Jourdain, B.; Aumont, B. (2004). Year-round records of gas and particulate formic and acetic acids in the boundary layer at Dumont d'Urville, coastal Antarctica. J. Geophys. Res., 109.
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Priestley, K.; Debayle, E.; McKenzie, D.; Pilidou, S. (2006). Upper mantle structure of eastern Asia from multimode surface waveform tomography. J. Geophys. Res., 111.
Keywords: Asian upper mantle; multimode surface waveform; craton; 7208 Seismology: Mantle; 7218 Seismology: Lithosphere; 7255 Seismology: Surface waves and free oscillations; 7270 Seismology: Tomography
Programme: 133
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. (2005). J. Geophys. Res., 110.
Keywords: polar ozone loss; UV radiation; polar vortex; 1610 Global Change: Atmosphere; 0341 Atmospheric Composition and Structure: Middle atmosphere: constituent transport and chemistry; 0340 Atmospheric Composition and Structure: Middle atmosphere: composition and chemistry
Programme: 209
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Fahlman, A.; Handrich, Y.; Woakes, A.J.; Bost, C.-A.; Holder, R.; Duchamp, C.; Butler, P.J. (2004). Effect of fasting on the VO2-fh relationship in king penguins, Aptenodytes patagonicus. Am. J. Physiol. Regul. Integr. Comp. Physiol., 287(4), R870–877.
Abstract: King penguins (Aptenodytes patagonicus) may fast for up to 30 days during their breeding period. As such extended fasting may affect the relationship between the rate of O2 consumption (O2) and heart rate (fH), five male king penguins were exercised at various speeds on repeated occasions during a fasting period of 24-31 days. In addition, O2 and fH were measured in the same animals during rest in cold air and water (4{degrees}C). O2 and fH at rest and O2 during exercise decreased with fasting. There was a significant relation between O2 and fH (r2 = 0.56) that was improved by including speed, body mass (Mb), number of days fasting (t), and a cross term between fH and t (r2 = 0.92). It was concluded that there was a significant change in the O2-fH relationship with fasting during exercise. As t is measurable in the field and was shown to be significant and, therefore, a practical covariate, a regression equation for use when birds are ashore was obtained by removing speed and Mb. When this equation was used, predicted O2 was in good agreement with the observed data, with an overall error of 3.0%. There was no change in the O2-fH relationship in penguins at rest in water.
Programme: 131;137;394
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Tocheport, A.; Rivera, L.; Chevrot, S. (2007). A systematic study of source time functions and moment tensors of intermediate and deep earthquakes. J. Geophys. Res., 112.
Keywords: Deep earthquakes; body waves inversion; source parameters; 7203 Seismology: Body waves; 7215 Seismology: Earthquake source observations; 7209 Seismology: Earthquake dynamics; 8120 Tectonophysics: Dynamics of lithosphere and mantle: general
Programme: 133
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Faccenna, C.; Rossetti, F.; Becker, T.W.; Danesi, S.; Morelli, A. (2008). Recent extension driven by mantle upwelling beneath the Admiralty Mountains (East Antarctica). Tectonics, 27.
Abstract: Northern Victoria Land is located at the boundary between an extended, presumably hot, region (West Antarctic Rift System) and the thick, possibly cold, East Antarctic craton. The style and timing of Tertiary deformation along with relationships with the magmatic activity are still unclear, and contrasting models have been proposed. We performed structural and morphotectonic analyses at the NE termination of northern Victoria Land in the Admiralty Mountains area, where the relationship between topography, tectonics, and magmatism is expected to be well pronounced. We found evidence of two subsequent episodes of faulting, occurring concurrently with the Neogene McMurdo volcanism. The first episode is associated with dextral transtension, and it is overprinted by extensional tectonics during the emplacement of large shield alkaline volcanoes. Upper mantle seismic tomography shows that the extensional regime is limited to regions overlying a low-velocity anomaly. We interpret this anomaly to be of thermal origin, and have tested the role of large-scale upwelling on lithosphere deformation in the area. The results of this integrated analysis suggest that the morphotectonic setting of the region and the magmatism is likely the result of upwelling flow at the boundary between the cold cratonic and the hot stretched province (WARS), at work until recent time in this portion of the northern Victoria Land.
Keywords: Antarctica; continental tectonics; faulting; mantle dynamics; seismic tomography; 7230 Seismology: Seismicity and tectonics; 8010 Structural Geology: Fractures and faults; 8107 Tectonophysics: Continental neotectonics; 7270 Seismology: Tomography; 8122 Tectonophysics: Dynamics: gravity and tectonics
Programme: 906
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. (2002). Measurement of the specific surface area of 176 snow samples using methane adsorption at 77 K. J. Geophys. Res., 107.
Keywords: 1863 Hydrology: Snow and ice; 3947 Mineral Physics: Surfaces and interfaces; 0399 Atmospheric Composition and Structure: General or miscellaneous; 0320 Atmospheric Composition and Structure: Cloud physics and chemistry
Programme: 437
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